Tube coating brush



Jun 21, 1932. C, STUBBS 1,863,950

TUBE coATING BRUSH Filed sept. 16, 1929 jiiiifilllll IE" s Patented June2l, 1932 UNITED srrsrrlsz's PATENi@ OFI-*ICE CHARLES H. STUBBS, OFBOSTON, MASSACHUSETTS, .ASSIGNOR T0 THE DAMPNEY COM- PANY OF AMERICA, OFBOSTON, MASSACHUSETTS, A CORPORATION OEl MASSA- cnUsET'rs TUBE COATINGBRUSH Application led September 16, 1929. Serial No. 392,837.

This invention relates to brushes, and more particularly to a brush foruse in coating the interior surfaces of the tubes of water tube boilers,condensers, and likeapparatus.

It isrecognized that tubes in water tube boilers and other apparatus canbe treated to advantage by coating the interiors thereof withaprotective coat of. a composition in the form of a paint, thiscomposition serving to protect the tube against the destructive actionof the liquid or fluid flowing therethrough.A

' tective composition should, for maximum efficiency, be distributeduniformly over -the entire interior surface of the tube, so as t0effectively cover the same. To accomplish this, the coating` brushshould be disposed parallel with the tube and should bear against 'theinner face thereof with uniform pressure throughout thelength of thebrush.

One of the main objectsV of my invention is to provide a tube coatingbrush of simple construction and operation, in which the sections ofthebrush Contact with the interior of the tube under uniform pressureand are disposed parallel to the tube. A further object is to provide abrush of this character, in which the brush sections are interconnectedin such manner as to aure equal pressure thereof against the interiorsurface of the tube. Further objects and advantages will appear from thedetailed description.

In the drawing:

Figure l is an elevation of atube coating brush structure in accordancewith my invention;

Figure 2 is an axial sectional view through the brush structure, partsbeing shown in elevation, in open or expanded condition for use in thetube; n A

Figure 3 is a section taken substantially on the line 3-3 of Figure l,on a reduced scale; an

Figure 4 is an outer end view of the brush head. 1

The brush proper is mounted upon a cylindrical head l provided at oneend thereof with a screw stud 2, by means of which the head is adaptedto be attached to a driven member, such as an air turbine, to be rotatedthereby. At its other end, the head is slotted diametrically to providetwo lateral flanges 3 disposed in .spaced parallel relation. Two links 4and 5 are pivotally secured at one end, between the flanges 3, by pivotpins 6.- One of these links is provided with a tooth or detent 7, whichextends into a depression or recess 8 in the other link 4. This tooth ordetent and the depression 8 coact to provide a gear connection betweenthe two links, which assures equal movement thereof. Each link ispivotally secured at its other end, by means of a pivot pin 9, to a coreor base member l0a of a brush section 10, which also comprises thebristlesL l0b secured in base 10 in a known manner. Base 10a isprovided, in its inner face, with a longitudinally extending groove 11,having a relatively deep arcuate portion l1 which receives the enlargedend portion of the link. Each brush section 'l0 is of substantiallysemi-cylindrical shape and, when the links 4 and 5 are disposed inparallel v relation, the two brush sections fit together with the linksdisposed in the grooves, as in Figure l. Each pin 9 is peened over orhead-V ed at each end, as at 12,y so as to beheld there,- by againstendwise movement.

In the use of this brush, after a suitable quantity of the coatingmaterial has been placed within the tube, the brush is inserted into thetube and is moved therethrough, being simultaneously rotated at asufficiently high speed to cause the brush sections 10 to swingoutwardly under the influence of centrifugal force into contact with thesurrounding wall of the tube. Since the two links 4 and 5 areinterconnected, so as to have 1 equal movement inopposite directions,the

bristles b of the brush sect-ions will be urged into contact with theinterior surface of the tube with equal pressure. Also, since the brushsections are pivoted to the links on axes parallel to the pivotalconnection between these links and the head and transverse to the axisof rotation of the head, the brush sections are free to swino about thepivot pins 9 into parallelism with the-tube. This means that, if thebristles of either of the 'brush sections should contact with theinterior of the tube at either end of such section, when the brushisifirst expanded by rotation thereof with the head, continued outwardmovement of the brush section would result in rocking of the same uponthe pivot pin 9 until the section has been moved into .parallelism withthe tube with the bristles throughout the entire length of such sectionin contact with the inner face of the tube. The. pivoting of the linksto the head on axes transverse tothe axis of rotation of the head and onopposite. sides of such axis, and the pivoting of the brush sectionstothe links on axes parallel to the axes of the pivotal connectionsbetween the links and the head, cooperate tol assure proper movement ofthe brush sections. into contact with the surrounding wall of the tubeand also assure 'i that such contact will extend throughout the lengthof the bristles of each brush section.

This greatly facilitates the application of the coating of protectivematerial to the interior of the tube. The interconnection between thetwo links assures that the pressure of the bristles. of the respectivebrush sections against the interior of the tube is equal, thus assuringuniform distribution of the coating Vmaterial upon the inner face of thetube.

In its broader aspects, my invention comprehends the provision of arotatable head and of brush sections, in conjunction with the .links orequivalent means pivotally secured at one end toy the head on axesextending transversely of the axis of rotation of said head and disposedat opposite sides thereof, the brush sections'being suitably connecte-dto the links at the other end thereof in such manner as tol be capableof movement relative Vto the links intosubstantial parallelism totheaxis of rotation of the head. More specifiaxis of rotation of head 1during rotation thereof. The brush sections will then be held in Contactwith the inner face of the tube, :during rotation of the head,throughout .under equal and uniform pressure.

the entire lengt-h of each brush section and This is indicated Iindotted lines and is designated by the reference character T.

By thus mounting the brush sections relative to the links, andconnecting the links for equal movement, the brush structure as a Wholeassures uniform distribution of the coating composition upon the innerface of the tube throughout an area of appreciable extent during eachcomplete rotation of the brush structure. As a result, with the brushrotated at moderate speed, the structure as a Whole can be insertedthrough and withdrawn from the tube at relatively high speed and yet,during such rapid insertion and Withdrawal, assures proper coating ofthe entire interior of the tube. By constructin the brush structurel inthe mannery illustrate and described, I thus obtain more uniform coatingof the interior of the tube than has heretofore been possible and permitof this being done more rapidly than is possible by the .use of coatingbrushes commonly employed for this purpose, thus effecting a materialsaving in time, which is an essential consideration in this art.

The links 4; and 5 are preferably provided with extensions 13 whichconstitute stop elements. These elements'cooperate with the Walls ofrecesses 11a to limit turning movement of the brush sections about pins,9..to ward extensions- 13, under certain conditions.

A protector 14 of suitable type is preferably disposed about head 1, asillustrated. This protector comprises an inner layer 15 of rubber, anintermediate layer 16v of fabric, and an outer layer 17 of rubber.

The protector has a snug fit about head 1 and is provided, in its innerend, with two notches 18 which snugly receive pins 19fscrewed orotherwise suitably secured in the head. In this manner the protector iseffectively secured on the head and, in the use of the Irl brush,provides a cushioning guard which effectively prevents contact of thehead 1 and associated parts with the tube. It will thus be seen thatpossibility of contact of the metallic parts of the brush with the tube,and possible resulting damage to either the brush or the tube, iseliminated.

What I claim is In a tube coating brush structure, a rotatable head,links pivoted at one end. to the head von axes transverse toand atAopposite sides of the axis of rotation thereof for movement toward andaway fromy each other, Opposed brush sections pivotally securedintermediate their ends to the links on axes transverse to the axis ofrotation of the head, and a cushion guard extending about the head.

In witness whereof, I here-unto subscribe my name this fourthy day ofJune, 1929-.

CHARLES H. STUBBS..

will be clear from Figure2, in which the tube Y l

